1. Field of the Invention
This invention relates to the cold end processing of glass sheets, and in particular to an automated system for cutting, breakout and edging a glass sheet at a single station without indexing the glass between manufacturing processes.
2A. Technical Consideration
Glass sheets are fabricated to various shapes to conform with the outlines required for fabricated products such as windows for automobiles or other vehicles, architectural windows, glass doors, etc. Typically, a flat glass sheet is positioned at a first station where the glass is scored along the outline of the desired glass shape. The glass sheet is then indexed to a second station where the undesired portions of glass, or salvage, are removed. The glass shape is then moved to a third station where the edge of the glass is ground to remove any sharp edges along its outline.
During this process, the glass is highly susceptible to misalignment during its continual indexing from one position to another position in the different operating stations. Generally the glass sheet must be continually realigned to insure that the glass is in the proper position for each operation. It would be useful to have a glass sheet cutting, breakout, and edging arrangement that maintains the glass at a single station thus eliminating the inherent problems associated with product indexing. In addition, it would be advantageous to incorporate numerical control technologies into such a system so as to enhance system flexibility.
2B. Patents of Interest
U.S. Pat. No. 3,343,436 to Cockrell teaches a control system for selectively operating cutting devices in a controlled sequence to cut a linearly moving glass sheet into glass sheets of smaller width along lines parallel to its direction of movement.
U.S. Pat. No. 3,453,097 to Hafner teaches a method of cutting glass wherein the glass sheet is moved continuously passed a laser beam which is focused upon the glass sheet. The glass absorbs the laser energy and converts it into sufficient heat to enable separation of the glass into pieces along the line swept by the laser beam.
U.S. Pat. No. 3,834,258 to Zumstein teaches an apparatus for cutting glass moving with relative motion with respect to the cutting tools. The glass plate is supported on a table and a bridge extending over the table carries the cutting tools which are displaceable in a longitudinal direction.
U.S. Pat. No. 3,921,873 to Dahlberg et al. teaches heating a glass sheet near a scored line to help propagate the score through the glass to help remove the edge of the sheet.
U.S. Pat. Nos. 3,932,962 and 3,991,636 to Devillers teach a control apparatus for a machine for cutting and grinding the edges of a glass sheet. In the cutting operation, the apparatus includes a horizontal table for supporting the glass sheet, a horizontal jig defining the cutting path, a freely displaceable carriage equipped with a cutting tool, and a motor adapted to produce the displacement of the carriage along the jig. In the grinding operation, the apparatus includes a conveyor belt for advancing the glass sheet and a rotary grinding tool on one side of the conveyor, positioned so as to come into contact with an edge of the work piece as it is conveyed passed the grinding tool.
U.S. Pat. No. 4,422,149 to Reinmold et al. teaches a process and apparatus for correcting the control program of ad automatic glass sheet cutting machine by accounting for and correcting any X and/or Y coordinate discrepancies.
U.S. Pat. No. 4,424,569 to Imazeki et al. teaches a numerically controlled method and apparatus for a machine tool of the type having a plurality of tools which move in unison with a fixed positional relationship with respect to one another. The invention requires only a current position register for one of the tools to maintain machining efficiency.
U.S. Pat. No. 4,466,562 to DeTorre and U.S. Pat. No. 4,495,845 to Sherby teach scoring of a glass sheet by passing the glass between an upper scoring wheel and a lower support wheel.
U.S. Pat. No. 4,502,125 to Yoneda et al. teaches a numerical controller for an angular slide grinding machine capable of precisely controlling dressing feed movements of a work table. The machine includes a wheel head carrying a dressing tool and a grinding wheel.
U.S. Pat. No. 4,577,539 to Bonacci teaches an apparatus for cutting sheets of plate glass with a digital control unit in which the centrifugal force to which the tool-bearing cart and cutting wheel carried on it are subjected is eliminated or reduced to a minimum by reducing to a minimum the mass of the tool-bearing cart in motion, and by making the cart move in a purely rectilinear trajectory so that the cutting wheel does not have to follow curved trajectories which generate centrifugal forces transverse to the trajectory to be followed.
U.S. Pat. No. 4,648,210 to Reinmold et al. teaches an apparatus for grinding the edges of a glass sheet including a grinding disc mounted to rotate in a tool holder which may be moved in relation to the axis of rotation of a rotary table. The disc is driven by a constant torque motor so as to apply a constant grinding pressure between the grinding tool and the glass sheet.
U.S. Pat. No. 4,672,874 to Gach teaches a scoring wheel rotatably mounted on an axle within a mounting bracket. The bracket assembly reduces the tendency for accumulation of glass chips between the scoring wheel and supporting bracket.
U.S. Pat. No. 4,698,088 to Bando teaches a numerically controlled glass plate fabrication machine wherein the glass plate is moved linearly on a work table to progressively move the glass sheet from a cutting station to a cracking station, and finally to a grinding station.